The network approach and interventions to prevent HIV among injection drug users.

OBJECTIVE To review human immunodeficiency virus (HIV) risk reduction interventions among injecting drug users (IDUs) that have adopted a network approach. METHODS The design and outcomes of selected network-based interventions among IDUs are reviewed using the network concepts of the dyad (two-person relationship), the personal risk network (an index person and all of his or her relationship), and the "sociometric" network (the complete set of relations between people in a population) and community. RESULTS In a dyad intervention among HIV-serodiscordant couples, many of which included IDUs, there were no HIV seroconversions. Participants in personal risk network interventions were more likely to reduce drug risks and in some of these interventions, sexual risks, than were participants in individual-based interventions. Sociometric network interventions reached more IDUs and may be more cost-effective than individual-based interventions. CONCLUSION Network-based HIV risk reduction interventions among IDUs, and others at risk for HIV, hold promise and should be encouraged.